A phlorotannin nanoparticle-hydrogel composite for enhanced oral delivery and treatment of ulcerative colitis

Designing innovative strategies for oral delivery of active compounds is particularly promising for the treatment of intestinal diseases such as ulcerative colitis (UC). However, obstacles like poor therapeutic efficacy, low bioavailability, and limited biocompatibility need to be addressed. Here, via the Schiff base reaction, we developed nanoparticles based on PT (PT NPs) and incorporated them into ascorbate palmitate hydrogels (AP-Gel) to create nanoparticle-hydrogel composites (PT NPs-Gel). In vitro studies showed that PT NPs-Gel reduced pro-inflammatory cytokines (NO, iNOS, TNF-α, and IL-1β), increased the anti-inflammatory cytokine IL-10, and enhanced antioxidant enzyme activities (SOD and CAT) with effect. In the DSS-induced UC mouse model, PT NPs-Gel significantly alleviated UC symptoms, improved the length of colon, and lowered the disease activity index (DAI) score. Histological analysis indicated that PT NPs-Gel protected the colonic epithelial barrier and reduced inflammation. The PT NPs-Gel formulation utilizes the biological properties of the hydrogel carrier to improve the bioavailability of active compounds and demonstrates effective anti-inflammatory and antioxidant properties, making it a promising oral delivery system for the treatment of UC and potentially other inflammatory bowel diseases.